The invention relates to an endoscope having a movable electrode supplied with high frequency current at the distal insulated end of the endoscope shaft.
Endoscope of this type are already known by means of which tissue in the vesica or on the cervic vesicae is removed by an electrode which is supplied with high frequency current and which is generally constructed in the form of a wire loop. In such transurethral operations, the tissue and the like is cut at the insulated shaft edge by means of the said electrode. It has been found in practice that when using the said insulating materials, it is impossible to prevent melting of the cutting shaft edge due to sparking on the loop-like electrode. As a result, notches and cup-shaped indentations are formed which can damage the mucosa. In addition, melting of the shaft edge gradually reduces the length of the shaft so that the loop-like electrode does not cut as well after prolonged use. However, the said known materials have the advantage that they do not break because they have a limited elasticity.
The problem of the present invention is to so improve the endoscope of the type indicated hereinbefore that the formation of notches and premature wear due to sparking on the electrode can no longer occur.